The present invention relates to vacuum cleaners. More particularly, the present invention relates to dual stage cyclonic vacuum cleaners used for suctioning dirt and debris from carpets and floors. Such vacuum cleaners can be upright, canister, hand-held or stationary, built into a house. Moreover, cyclonic designs have also been used on carpet extractors and “shop” type vacuum cleaners.
Upright vacuum cleaners are well known in the art. The two major types of traditional vacuum cleaners are a soft bag vacuum cleaner and a hard shell vacuum cleaner. In the hard shell vacuum cleaner, a vacuum source generates the suction required to pull dirt from the carpet or floor being vacuumed through a suction opening and into a filter bag or a dust cup housed within the hard shell upper portion of the vacuum cleaner. After multiple uses of the vacuum cleaner, the filter bag must be replaced or the dust cup emptied.
To avoid the need for vacuum filter bags, and the associated expense and inconvenience of replacing the filter bag, another type of upright vacuum cleaner utilizes cyclonic air flow and perhaps one or more filters, rather than a replaceable filter bag, to separate the dirt and other particulates from the suction air stream. If filters are used, they would need infrequent replacement.
While some prior art cyclonic air flow vacuum cleaner designs and constructions are acceptable, the need exists for continued improvements and alternative designs for such vacuum cleaners. For example, it would be desirable to simplify assembly and improve filtering and dirt removal.
Accordingly, the present invention provides a new and improved upright vacuum cleaner having a dual stage cyclonic air flow design which overcomes certain difficulties with the prior art designs while providing better and more advantageous overall results.